Electric toaster



Nov. 4, 1952 w. A. II-IUMPHREY ELECTRIC TOASTER 5 Sheets-Sheet 1 Filed Jan. 2, 1948 INVENTOH. Warm/z A. Humphrey ATTORNEY.

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Nov. 4, 1952 w. A. HUMPHREY ELECTRIC TOASTER 5 Sheets-Sheet 2 Filed Jan. 2, 1948 l I L l h I Vrre) A. Humphrey n m 0 T T A Nov. 4, 1952 w. HUMPHREY ELECTRIC TOASTER Filed Jan. 2, 1948 5 Sheets-Sheet 3 INVENTOR. Warren A. Humphrey ATTORNEY.

W. A. HUMPH REY ELECTRIC TOASTER Nov. 4, 1952 5 Sheets-Sheet 4 Filed Jan. 2, 1948 INVEN TOR. Z/Warren A Humphrey ATTORNEY.

Nov. 4, 1952 w. A. HUMPHREY 2,616,357

ELECTRIC TOASTER Filed Jan. 2, 1948 s Sheets-Sheet s M Calumet I N V EN TOR. l Vrrcn, A. lfumphre yw -sw ATTORNEY.

Patented Nov. 4, 1952 ELECTRIC TOASTER Warren A. Humphrey, Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio, a

corporation of Ohio Application January 2, 1948, Serial No. 206

' 2 Claims. 1

This invention relates to toasters and more particularly to a thermal timer for timing the duration of successive toasting intervals whereby toast may be prepared of the same degree of brownness for each succeeding toasting operation regardless of the number of successive toasting operations or of the manual setting for preparing light, medium, or dark toast.

Thermal timers for toasters which operate on the heat-up principle of operation are known in the art. Such timers time the toasting interval by the time it takes for a thermally responsive element to be heated to a predetermined high temperature. That is, the toasting interval is initiated simultaneously with the energization of the heater for the thermally responsive element and is terminated when the thermally responsive element is heated to a predetermined higher temperature.

Such timers have the inherent disadvantage that they tend to over-compensate. That is, as the toaster is operated repeatedly in rapid succession, the toaster as a whole heats up and acquires residual heat. This residual heat aids in the toasting operation so that the toasting interval should be sequentially shortened after the first toasting operation. However, the thermal timer itself also heats up and at a faster rate than the toaster as a whole. If the same quantity of heat is supplied to the thermal timer for each succeeding toasting operation the timer acts faster and faster in advance of the toasting rate even though the toaster as a whole is also acquiring residual heat. As a result the toast is underdone after the first toasting operation unless some means is provided for preventing it.

According to the present invention the thermal timer is initially heated by two heaters to heat the thermal timer for properly timing the first toasting operation. As the toaster heats up with rapid repeated use, one of the heaters is deenergized at the proper time during the timing of a toasting interval depending upon the temperature of the toaster so that toasting intervals after the first are prolonged sufiiciently to compensate for the tendency of the thermal timer to over-compensate. The time of the deenergization of the second heater depends entirely upon the temperature of the toaster as a whole. It may .be deenergized during the first toasting operation starting with a cold toaster but in such a case for succeeding toasting operations it will be deenergized much earlier in the toasting cycle.

Thermal timers of the heat-up type also have the disadvantage that it is necessary for the operator to wait until the thermal timer has cooled before a succeeding toasting operation can be begun. The length or the period of waiting may be shortened by providing some means for quickly cooling the thermally responsive element but it is still necessary for the operator to wait until the thermally responsive element has cooled to a proper low temperature.

According to another feature or this invention the operator may begin a new toasting operation immediately after a preceding one without waiting for the thermally responsive timer to cool. The toast carriers will be latched in toasting position regardless of the thermal condition of the thermal timer. The toasting operation will then proceed automatically without any further attention from the operator even though the thermal tmier has not yet cooled. In fact the operator need not be aware of that fact but may begin a second toasting operation immediately ai'ter the first.

According to another object of this invention manually adjustable means is provided for varying the heat applied to the thermal timer during a toasting interval in adjusting the timer for preparing light, medium, or dark toast upon which is interposed thermally responsive means responsive to toaster temperature for also varying the heat applied to the thermal timer to compensate the thermal timer so that it will produce the same color of toast regardless of the residual heat in the toaster from previous toasting operations.

Other objects and advantages of this invention will become apparent as the description proceeds when taken in connection with the accompanying drawings in which:

Figure 1 is a perspective of the toaster and timer of this invention with the parts broken away to better show the details;

Figure 2 is a longitudinal cross-sectional view of the toaster and timer of Fig. 1;

Figure 3 is a front plan view of the timer of this invention with the walls of the toaster broken away to show the details of the timer with the thermal timer in cold position and the toast carriers in toasting position;

Figure 4 is a view similar to Fig. 3 showing the thermal timer in hot position and the toast carriers in toasting position;

Figure 5 is an exploded view showing the details of the latch release mechanism of this invention; and

Figure 6 is a wiring diagram showing how the main heaters and auxiliary heaters are electrically connected.

Referring to the drawings the reference numeral it represents the base of the toaster made of an insulating moldable material, such as hard rubber, a phenolic condensation product, or other similar moldable insulating material. Mounted on the peripheral edge ll of the base It! is the lower edge of an appearance housing l2 having bread receiving slots IS in its top. Mounted on a peripheral ledge l4 inwardly of the edge ll of base it is a base plate H5. The base plate [5 supports, and the appearance housing 52 houses, the entire mechanism of the toaster and timer of this invention.

A partition [6 divides the interior of the toaster into a mechanism compartment I1 and a toasting oven l8. Secured at their bottom ends to the base plate I5 are a pair of vertically extending rods l9 which are secured at their upper ends to the partition it by a bracket 2d. The .rods 19 form guides for the vertical reciprocation of a carriage plate 2| in a manner Well known in the art.

Bent rearwardly from the carriage plate 2! are a pair of lugs 23 to which are attached bread carriers 24. Also bent rearwardly from the carriage plate 2! are a second pair of lugs 25 to which are attached a pair of arms 21 by bolt and slot connections 26. The partition 66 is provided with two pairs of vertically extending slots 23 and 29 to provide forthe vertical reciprocation of the carriers 23 and the arms 21.

,At their rearward ends the arms 27 are pivoted at 30 to rearward extensions 3! of the side walls of the toasting chamber [8 and at their forward ends are extended forwardly, at 32, through a vertically extending slot 33 in the front of the appearance housing l2. A manipulating handle 34 is attached to the forward extensions 32 of the arms 27 outside of the appearance housing 12.

The forward ends of the arms 21 and the associated parts including the carriage plate 2i and bread carriers 2d are spring-biased upwardly to bread receiving position in any suitable manner such as by springs 35 anchored at their upper ends to a lug 3E and at their lower ends to the arms 21 as shown in dotted lines in Fig. 2. A bumper spring 3? is secured to a lug 22 to dampen the upward movement of the carriage plate 2| as it moves upwardly under the bias of springs 35. Main heating elements 38 are positioned on opposite Sides of the bread carriers 24 to perform the toasting function.

Slidably mounted on the carriage plate 2! by pin and slot connections All is an auxiliary plate 4! which is normally held in its downward position, against a suitable stop M struck forwardly from the carriage plate 2 i, by a spring 42 (Fig. 2) anchored at its upper end to the pin 43 secured to the auxiliary plate ll and at its lower end to the-carriage plate 2! in any suitable manner such as by a lug struck rearwardly from the carriage plate 2 I.

Extending forwardly from the auxiliary plate il are a pair of arms 45 carrying a pair of reflectors 46 and 61. Also carried by the arms 55 immediately below'the reflectors 36 and $1 is a high heating capacity electrical heater 48 and a low heating capacity electrical heater ill.

Carried by the arms- 45,-in front of the reflectors 46 and ll and heaters 48 and 49 is a switch mechanism generally indicated by the reference numeral 5% (Fig. 3). The switch 55] comprises a body 5i carrying a pair of spring mounted contacts 52 and 53. The position of spring contact 52 is adapted to be adjusted by a screw 54 which constitutes a factory adjust- 4 ment. The spring contact 53 is adapted to be actuated by bimetallic element 5'5. As shown in Fig. 3 the bimetallic element 55 is attached at its left hand end to a spring 58 and at its opposite end is anchored to the base 51. The central portion of the bimetallic element 55 is bowed upwardly and has a button 56 thereon to contact the spring arm of the spring contact 53.

The spring 58 is attached to the switch housing 5! at 57 and has a projection 59 extending through the bottom plate 5'! of the housing 5|.

Upward movement of the projection 59 will apply a spring pressure to the contact button 56 and tacts 52 and 53 make and break electrical contact as will presently appear.

Extending outwardly and rearwardly from one side of the auxiliary plate ll is an arm 15 having a protuberance 18 adapted to contact a spring arm I? mounted on the base plate l5 and carryinga bridging contact I3 adapted to bridge fixed contacts 19 insulatedly mounted on the base plate 15.

The projection 59 is adapted to be contacted, in a manner which will presently appear, by a cam [it on the upper end of a vertically extending shaft 6! rotatably mounted on the base plate It and having a manipulating knob 62 directly connected to the shaft 6| with its edge extending through an opening 63 in the front of the base it for ease in manipulation.

Rigidly secured to the base plate [5 immediately below the reflectors 4t and 41 and the elec-'- tric heaters 48 and 49 is a bracket generally indicated by the reference numeral 65. The bracket 65 includes side members 66 and 61, end member 88 and a pair of upwardly extending projections 69 and NJ at its opposite end.

The side members 66 and 61 of bracket 65, have depressions H for pivotally supporting the lower end of a plate '62 having a depression 13 therein for receiving one end of a bimetallic snap-acting thermally responsive timer [4, the opposite end of which is received in a depression 14 in the end 68 of bracket 65.

Spring pressure is applied to the ends of the bimetallic element it by a compression spring 86 surrounding the threaded end of an eye bolt ti extending through a central opening in the pivoted member 12 and pivotally attached to the side members it and 61 by a pin 82. A nut 83 applies pressure to the outer end of the spring which, in turn, applies pressure to the pivoted arm l2 and thus to the ends of the thermally responsive timer I l.

A latch lever 84 lies rearwardly of the side member 6! and is pivoted to the side members 66 and 57 by a pin extending through openings 65 and 81 in the side members 66 and 61 respectively. The lever 84 is spring-biased clockwise by a spring 88. Pivoted to the pin 85 15 a latch hook 89 having limited pivoted movement relative to the latch lever 84 by means of a pin and slot connection 90 which constitutes a fac-- The latch hook 89 has a hook 92 and a cam 93 adapted to cooperate with a lug 94 struck forwardly from the carriage plate 2| as will presently appear. The latch lever 84 has a lug 95 which cooperates with alug 96 on a latch release lever 9'! as will be explained presently; Latch release lever 91 is pivoted at its right hand end' aerasw between the sides 88 and 51 of the bracket 85 as at 98 by a pin 99 extending through openings in upwardly extending flanges I and IOI of the latch release lever 91. The flanges I00 and i0I have openings I02 for receiving a pin I03 extending through openings in the legs of an inverted U-shaped member I04 having its bight portion I overlying the central portion of the bimetallic timer I4. The legs of the member I04 are bent inwardly beneath the central portion. of the bimetallic elements I4 as shown at I05 for a purpose to be hereinafter described.

Extending upwardly from the flange I00 of the latch release lever 91 is a lug I01 having a rearwardly extending ledge I08 and an upwardly extending portion I09 with a lug IIO extending rearwardly therefrom. Pivoted to the upward extension portion I09 by a rivet III and springbiased against the lug IIO by the spring H2 is a link I08 having a hooked end II 3 for a purpose to be hereinafter described.

Pivoted to the rear side of the inner wall 5'! of the bracket 85 by a pin I I4 is a link I I5 springbiased counterclockwise by a spring H6. The link II 5 has tabs II 8 and III bent rearwardly therefrom. The tab I I8 forms one abutment for the spring IIS and the opening I I9 in the wall 61 the other. Extending forwardly and downwardly from the auxiliary plate M is a tab I28 which cooperates with the tab II8 in a manner to be presently described.

The right hand end of latch lever 84 is extended downwardly through the base plate I5 and has a lug I2I thereon which cooperates with a cam I22 mounted on the end of the shaft I 23 rotatably mounted so as to extend through the front of the base I9. A manipulating knob I24 is attached to the end of the shaft I23 outside of the base I0. This arrangement is for the purpose of manually releasing the toaster carriage independently of the timer as will later appear.

Referring to Fig. 6, one side I25 of the power line is connected to one of the fixed contacts 19. The other fixed contact I9 is connected to one side of the main heaters 38 by a conductor I25. The other side I29 of the power line is connected to the other side of the main heaters 38 by conductor I2'I, conductor I28, high heating capacity auxiliary heater 48 an dconductor I30 so that the main heaters 38 and the high heating capacity auxiliary heater 48 are connected in se ries. The low heating capacity auxiliary heater 49 is connected in parallel with the high heating capacity auxiliary heater 48 by conductor I3I, contacts 53 and 52, conductor I32, heater 49 and conductor I33.

Operation Fig. 1 shows the parts in the position they occupy when the timer and toaster are cold and the bread carriers are in receiving position.

Bread is inserted through the openings I3 so as to rest on carriers 24. The manipulating handle 34 is moved downwardly so as to move the carriers 24, the carriage plate 2I and the auxiliary plate 4I downward to toasting position against the bias of springs 35.

The auxiliary plate H 'is moved along with the carriage plate 2I by the spring 42 which holds the pin 43 at the lower end of the pin and slot connection unless prevented as will hereinafter be explained. As the auxiliary plate 4I moves downwardly the lug I20 will engage the lug II8 of link H5 and pivot it clockwise against the bias of the spring II5.

In the movement of the carriage plate 2! downwardly the lug 94 extending forwardly from the carriage plate 2I will engage the cam 93 and move the latch lever 84 counter-clockwise until the lug 94 moves below the hook 92 at which time the spring 88 will return the latch lever 84 to its original position so as to position the hook 92 above the lug 94 and latch the carriers 24, carriage plate 2I and auxiliary plate M in toasting position.

Movement of the auxiliary plate 4I to downward position will position the reflectors 48 and 41 and the auxiliary heaters 48 and 49 immediately above the bimetallic timer I4. Movement of the auxiliary plate 4I downwardly will also cause the lug I6 to engage the springarm I1 and bring the bridging contact I8 into contact with the fixed contacts I9 and simultaneously energize the main heaters 38 and the auxiliary heaters 48 and 49.

Heat from the main heaters 38 will perform the toasting function and heat from the auxiliary heaters 48 and 49 will be radiated and also reiiected to the bimetallic timer I4 so as to cause its central portion to move downwardly slowly. The member I 04 will also move downwardly with the central portion of the bimetallic element I4 as it comes in contact with the inturned portions I05 of the member I04. This will slowly pivot the latch release lever 91 counter-clockwise.

Heat from both of the auxiliary heaters 48 and 49 will heat the bimetallic element "I4 fairly rapidly during the first part of the toasting interval. Toward the end of the first toasting interval heat from the main heaters 38 will raise the temperature of the toaster as a whole quite considerably. This heat will be transmitted to the casing 5| of the switch 50. This will cause the bimetallic element 55 to flex downwardly and cause the abutment 55 to move away from the spring contact 53 and permit it to move away from the contact 52 so as to open the circuit to the low heating capacity auxiliary heater 49.

Heat will continue to be transmitted to the bimetallic timer I4 from the high heating capacity auxiliary heater 48 but at a slower rate until the bimetallic element I4 reaches its dead-center position at which time it will be snapped to its lower over-center position by the action of the spring 80. The snapping of the central portion of the bimetallic element I4 to downward position will carry the member I94 with it and quickly move the latch release lever 9? to its extreme counter-clockwise position so that the lug 96 will strike the lug On the end of the latch lever 84 and move it counter-clockwise so as to move the hook 92 from above the lug 94 and permit the bread carriers 24 to be returned to receiving position under the bias of springs 35. The latch 84 will immediately return to its original position under the action of the spring 88 because the bimetallic element I4 will recover sufficiently to disengage the lugs 95 and 96.

Movement of the carriers to receiving position will also carry the heaters 48 and 49 upwardly away from the bimetallic element I4 to permit it to cool more quickly.

If now the operator desires immediately to institute a second toasting operation, bread is inserted and the manipulating handle 34 moved downwardly as before. The lug 94 of carriage plate 2| will be engaged under the hook 92 of latch lever 84 as before. However, as will presently appear, the auxiliaryplate M will be pre- 7 Vented from moving to its lowermost position so that the bridging contact 18 will not be brought into engagement with the fixed contacts 19 to energize the toaster until the bimetallic element 14 has cooled and moved back to its upward overcenter position.

When the auxiliary plate 4! moved upwardly the lug I20 was removed from engagement with the lug H8 of link H5 whereby the link H5 was moved counter-clockwise by the spring IS. The bimetallic element 14 being in its downward overcenter position at this time the'link Hi5 will also be moved downwardly since it is carried by the latch release lever 91. Counter-clockwise movement of the link H5 will cause the lug I H to ride over the pointed end of the link I06 until it is behind the hook I [3 whereby the spring H2 will move the link I86 clockwise to engage the hook H3 over the lug H! of link H5.

When the handle 34 is moved downwardly again the lug I29 on the auxiliary plate M will engage the lug H8 of the link H5. Since the link H5 is held in its counter-clockwise position by the hook H3 the movement of the auxiliary plate 4| downwardly will be arrested and the spring 42 elongated. This will prevent the lug Hi from closing contacts 78 and 19 as previously described.

The bimetallic element 14 will cool within a few seconds and snap upwardly again to its upper over-center position. The central portion of the bimetal 14 will carry the member IM, latch release lever 91 and link It upwardly with it so that the hook i i 3 will be removed from in front of the lu Hi and permit the spring 42 to move the auxiliary plate 4! downwardly by rotating the link H5 clockwise. The lug 16 will engage the spring 71 and bring the bridging contact 18 against the fixed contacts 79 and reenergize the entire toaster without any attention from the operator.

Heat will be transmitted from the heaters 48 and 49 to the bimetallic timer M as before. However, since the toaster as a whole is hotter than for the first toasting interval the switch 50 will also be hotter so that the contacts 52 and 53 will be separated to deenergize the heater d9 earlier in the cycle than for the first toasting interval. This will prolong the toasting interval over that which would otherwise take place. By a proper design this prolongation will be just sufficient to compensate for the tendency of the bimetallic timer 14 to over-compensate. Eventually the bimetallic timer M will again snap downwardly to time the second toasting operation in the same manner as described in connection with the first toasting interval.

The operator may continue to toast bread in rapid succession without waiting for the bimetallic element 14 to cool and as is apparent need not even know that it has not cooled. This arrangement. assures that the bimetallic timer M will always be in its proper cool condition before the heaters are energized so that each toasting interval will be properly timed regardless of how the toaster is used.

The use of the multiple heaters with means for cutting one out of operation as the toaster heats up assures that the toast will be done to the same degree regardless of the time interval between toasting operations and of the number of times the toaster is operated in rapid succession.

If at any time the operator should desire to examine the toast during a toasting operation or to stop the operation of the toaster during the toasting operation it is only necessary to rotate the knob I24 to cause the cam I22 to rotate the latch lever 84 counter-clockwise to release the bread carriers for movement to receiving or inspecting position. The manipulating handle 34 may immediately be pushed downwardly again without materially affecting the operation of the toaster.

If the operator desires to prepare light toast the knob 62 is rotated so that a high point of the cam 60 will engage the projection 59 and raise the spring arm 58 upwardly so as to flex the bimetallic element 55 upwardly and apply more pressure to the spring contact 53. Under these conditions the bimetallic element 55 will have to be heated up more before the contacts 52 and 53 are separated so that the heater t9 will remain on longer during each toasting interval. This will cause the bimetallic timing element H to move to its lower over-center position sooner than before and thus shorten the toasting interval to produce light toast.

If medium or dark toast is desired the knob 62 is rotated so that a lower point on the cam ti) engages the projection 59 so as to lessen the pressure on the spring contact 53. This will cut the heater 49 out of circuit sooner so that it will take a longer time for'the bimetallic element 14 to terminate the toasting interval. This adjustment will produce medium or dark toast depending upon the setting of the cam 60.

From the foregoing it can be seen that this invention provides manually adjustable means for varying the heat applied to the thermal timer duringa toasting interval in adjusting the timer for producing light, medium, or dark toast upon which is interposed thermally responsive means for also varying the heat applied to the thermal timer so as to compensate the thermal timer to produce the same color of toast regardless of the residual heat in the toaster as a whole.

While I have shown but a single embodiment of my invention it is to be understood that this embodiment is to be taken as'illustrative only and not in a limiting sense. I do not wish to be limited to the particular structure shown and described'but' to include all equivalent variations thereof except as limited by the scope of the claims.

I claim:

1. A toaster comprising, bread carriers movable from receiving to toasting position, a ther-.

mal timer for timingthe duration of successive toasting intervals, said timer being movable from a cold position to a hot position upon being heated and back to its cold position upon being cooled, a plurality of heaters for said thermal timer, means formoving said carriers to toasting position, means for latching said carriers in toasting position, means actuated by movement of said carriers to toasting position for energizing said' heaters, compensating thermal means for cutting one oi said heaters out of circuit responsive to rises in toaster temperature and means actuated by movement of said timer to its hot position for releasing said latching means.

2. A toaster according to claim 1 including manually actuatable means for releasing said latching means independently of said timer.

WARREN A. HUMPHREY.

(References on following page) 9 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,198,133 Smith Apr. 23, 1940 2,209,768 Dillman July 30, 1940 2,302,117 Gomersall Nov. 17, 1942 Number 10 Name Date Hall Nov. 17, 1942 Seharf July 27, 1943 Fischer Nov. 21, 1944 Sardeson Jan. 14, 1947 McCullough May 23, 1950 Scharf June 26, 1951 Humphrey June 26, 1951 

